1. Technical Field
The present invention relates to a fluid discharge device for discharging a fluid from nozzles, a nozzle inspection method, and a medium on which a nozzle inspection program is recorded.
2. Background Technology
In inkjet printers and other fluid discharge devices, nozzles are inspected based on voltage changes caused by ink discharged from the nozzles, and in cases such as when the nozzles omit dots, a cleaning process or another restorative process is executed as maintenance. Possible examples of the cause of ink not being discharged normally from the nozzles include the surface of ink (the meniscus) exposed in the nozzles being open to the atmosphere, causing the solvent to evaporate and the ink to thicken; and air bubbles getting into the pressure-generating chambers or the like, in which case the pressure changes in the pressure-generating chambers are absorbed by the air bubbles. Therefore, when nozzles that do not normally discharge ink are detected in the discharge inspection process, a restorative process is performed on the nozzles in order to restore the nozzles to the normal state.
For example, in the fluid discharge device disclosed in Patent Citation 1, cleaning boxes are provided, one for each of a plurality of nozzle rows, electrodes are disposed on the cleaning boxes, and the electrodes connected to means for detecting voltage changes caused by fluid discharged from the nozzles are switched to determine whether or not fluid has been discharged. A cleaning process is executed for nozzle rows determined to have not discharged fluid.
In the fluid discharge device disclosed in Patent Citation 2, when a nozzle inspection is performed, a print head is controlled so that ink droplets are discharged from the nozzles into a cap, and a determination of whether or not ink droplets have been discharged normally from the nozzles is made by comparing a threshold and a voltage signal derived from a differential between voltage signals from electrodes that have caused ink droplets to be discharged from among the plurality of electrodes, and voltage signals from electrodes that have not caused ink droplets to be discharged.
In the fluid discharge device disclosed in Patent Citation 3, when an uninspectable state has been detected, wherein the inspection means for inspecting whether or not there are any problematic nozzles cannot obtain the necessary inspection precision, the gap between a discharge means and an inspection electrode is adjusted to a width such that the inspection means can transition to an inspectable state.
In the fluid discharge device disclosed in Patent Citation 4, the peak values of voltage signals inputted from electrodes are held, the held peak values are added, and when a nozzle inspection is commanded, the print head is controlled so that a predetermined number of droplets are discharged from the nozzles, and the state of discharge of the nozzles is determined along with this control on the basis of the value obtained by adding the peak values.
In the fluid discharge device disclosed in Patent Citation 5, a print head is driven so that ink is discharged from any nozzle with a timing of an interval time period when nozzle inspection is performed, that is, a timing whereby a counter waveform is generated for negating a residual waveform which follows the main signal waveform of electrical changes.
Japanese Laid-open Patent Publication No. 2009-226616 (Patent Document 1), Japanese Laid-open Patent Publication No. 2009-226620 (Patent Document 2), Japanese Laid-open Patent Publication No. 2009-196291 (Patent Document 3), Japanese Laid-open Patent Publication No. 2009-226619 (Patent Document 4), and Japanese Laid-open Patent Publication No. 2010-179543 (Patent Document 5), are examples of the related art.